The present invention relates to computer software utility programs, and more specifically to a machine and method for producing a swept volume model in computer aided design and computer aided manufacture (CAD/CAM) software systems.
While using CAD/CAM applications it is often desirable to model the spatial inclusion or total volume a moving part will occupy during travel. The spatial inclusion of a moving part can be referred to as the swept volume. It is useful to determine the envelope or boundaries of a swept volume in order to design in adequate clearances for a part. Clearances are necessary, for example, to avoid unanticipated contacts of a part in motion with surrounding objects. In addition, accurate modeling of a swept volume allows for efficiency in terms of space cost. It is often useful to design a feature as compact as possible.
In some currently available systems, parts in motion can be modeled using multi-instantiation of the moving object. This technique produces models of a part at several instants during the part motion. As the number of instantaneous models produced increases the smoother a transition from one model to the next. Acceptable quality using these techniques tends to be processor intensive, requiring the creation of multiple images of the part.
Another technique uses multi-instantiation of a moving object combined with Boolean operations. This technique improves on the straight multi-instantiation model by allowing for extrapolation from one instantaneous model to another. The extrapolation can smooth the surface representation of the resultant model. However this modeling technique still involves creation of multiple instantaneous models and requires intensive processing.
Other approaches include use of voxel representation of a swept volume or use of a marching cubes algorithm.